Snow making apparatus

ABSTRACT

In a snow making apparatus, a metal snow gun housing is provided with independent air and water chambers therein for supplying air and water under pressure. Nucleating nozzles are provided in the housing which have an air chamber therein with side wall apertures for access of air under pressure to the air chambers. A jet stream of water is injected into the air chamber from a small water jet aperture which is axially aligned with an exterior nozzle aperture at the opposite end of the air chamber so that the water jet ejects through the exterior nozzle aperture without engaging sides thereof for thereby intimately mixing the air and water together as they exit the exterior nozzle aperture to finely nucleate the water spray exiting the snow gun. The water supplying the water spray is filtered and the gun is provide with a removable access for the filter.

CROSS REFERENCE

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 10/218,801, filed Aug. 14, 2002.

BACKGROUND OF THE INVENTION

[0002] This invention relates to snow making apparatus, and moreparticularly, to snow making apparatus of the type which utilizes, atleast in part, internal mixing of air and water under pressure.

[0003] Many different devices have been devised and used for“artificially” producing snow or for producing “man-made” snow. Suchdevices are utilized at ski resorts to supplement the supply of naturalsnow on ski trails. Whether the snow making apparatus is situated atground level or atop a support tower, they are generally referred to as“snow guns” in the industry and they all typically produce snow byprojecting a mixture of air and water under pressure in the form of afine atomized water spray into the surrounding sub-freezing ambientatmosphere. The snow guns are of basically two types, one wherein theair and water are internally mixed before spraying into the ambientatmosphere and a second wherein the air and water are externally mixedin the ambient atmosphere such that water spray droplets are projectedinto a stream of cold air under pressure. The present invention relatesto the type of snow making apparatus or snow gun which utilizes externalmixing techniques with all the advantages of internal mixing. Internalmixing and external mixing each have their own advantages anddisadvantages.

[0004] Internal mixing of the air and water under pressure allows forexcellent control of the atomization process. The resulting plume ofatomized water which is formed in the exterior atmosphere is made up ofuniformly sized well frozen nuclei. To the contrary, a wide variety ofdroplet sizes are found in the nucleating plume generated throughexternal mixing of air and water. In addition, with external mixing ofair and water from separate streams under pressure, high winds tend todeflect the air and “strip” the air from making full and efficientcontact with the water spray in such external mixing designs.Accordingly, internal mixing tends to be more efficient.

[0005] Through the use of internal mixing designs, nuclei or ice seedcrystals are able to be formed at a higher ambient temperature than ispossible through the use of external mixing. The result is betterquality snow at equal or higher temperatures.

[0006] However, a number of problems have been encountered in theindustry with internal mixing snow guns or snow making apparatus.Freeze-up of the nozzle in some prior art internal mixing snow gunstends to be more likely than incurred with external mixing apparatuswhich is properly configured. With many existing internal mixingdesigns, freeze-up is common as moving ice crystals block the nozzle andthe mixing or nucleation nozzle must be constantly heated by one meansor another in order to keep the nucleation nozzle operating. Heating thenucleation nozzle is a major disadvantage or limitation because not onlydoes it increase the manufacturing cost and operating complexity of theunit, but significantly limits the product's field and areas of use. Inaddition, ski resorts or ski areas do not normally have electricity onthe ski slopes which is available for use with the operation of snowguns.

[0007] In addition, internal mixing snow guns also tend to be easilyclogged, and they also are designed whereby one cannot operate the snowgun with water only when the ambient subfreezing temperatures areadequately low, since when one turns off or significantly lowers thepressure of the air supply the water will back down the air supply tubeand freeze in the air supply line. For example, it is apparent that thisproblem exists with the design illustrated in U.S. Pat. No. 5,083,707.

[0008] It is therefore an object of the present invention to eliminateor at least greatly reduce the aforementioned disadvantages of internalmixing snow guns and to further provide an external mixing designwherein water may be directed out of the snow gun without the assistanceof compressed air if so desired without unfavorable consequences and toalso produce more and better quality snow at higher temperatures withless consumption of compressed air and water.

SUMMARY OF THE INVENTION

[0009] The snow making apparatus of the present invention utilizes waterand air under pressure to artificially produce snow and is generallycomprised of a metal snow gun housing having independent air and waterchambers therein for supplying an air-water under pressure to at leastone, and preferably multiple, nozzles in the housing for spraying airand water externally to produce snow in sub-freezing ambient atmosphere.The supplied air pressure is normally at least 75 psi and the suppliedwater pressure is normally at least 150 psi. At least one, andpreferably multiple, nucleating nozzles are provided in the snow gunhousing and include a nozzle housing having an air chamber therein foreach nucleating nozzle. Each air chamber has at least one aperturethrough its side walls whereby one or more apertures register with theair chamber within the snow gun housing for access of air under pressuretherethrough into the air chamber. The air chamber has an external endand an internal end wherein a water aperture is provided on the internalend with a forward end of the water aperture axially exposed to theinterior of the mixing chamber. The rearward end of the water apertureis exposed to the water chamber within the snow gun housing forprojecting a jet stream of water under pressure through the wateraperture and on into the air chamber. An exterior nozzle is provided onthe nozzle housing at the external end of the air chamber and has anozzle aperture therethrough which is axially aligned with the wateraperture. This exterior nozzle aperture exits from the snow gun housingto ambient atmosphere. A removable filter closes off the rearward end ofthe water aperture for filtering the water supplied from the waterchamber and an access plug is provided in the snow gun housing andpositioned for access to the filter for servicing or removal.

[0010] This nucleating nozzle combination directs the water jet streamfrom the water aperture axially through the larger exterior nozzleaperture without engaging the sides of the aperture which createsextremely fine homogeneous nucleation of the water exiting the exteriornozzle aperture with the air under pressure into ambient atmosphere forthe manufacture of quality snow. In addition, this fine nucleated sprayis also effectively utilized to atomize additional water sprays providedon the external areas of the snow gun housing in order to provide goodquality snow at less expense due to the reduction of air and waterrequired normally to manufacture quality snow, and further due to thefact that this fine atomization is effective to convert more of thewater to snow.

[0011] In general use, the nucleating nozzle of the present inventionwill normally be used in combination with at least one additionalprimary water nozzle in the snow gun housing which is positioned forspraying water from the water chamber to the ambient atmosphere forinteraction with spray from the nucleating exterior nozzle for extremelyfine atomization of the primary water spray.

[0012] The internal nozzle housing is economically manufactured of asingle metal block including a plurality, such as three, of thenucleating nozzles therein with the rearward ends of these waterapertures exiting to a common single rearward end cavity which is closedoff by a filter to prevent clogging of the fine water jet apertures. Theexterior nozzles are also removable so that they may be replaced,repaired or unclogged. Under general operating conditions, the filtermight typically be comprised of a metallic mesh having filter aperturesof no more than 0.010 inches, which is also the diameter of thenucleating water jet stream apertures. This assures that the small waterapertures will not become clogged. The filter is threadably received inand secured to the nozzle housing.

[0013] In this specific given example, the water jet aperture wasselected to be 0.010 inches in diameter and the exterior nozzle aperturemight typically be selected to be approximately 0.060 inches indiameter. This arrangement permits the sharp water jet stream to exitthrough the exterior nozzle aperture without engaging sides thereof andto thereby intimately intermix with air under pressure from the airchamber as they exit the exterior nozzle aperture to create an externalplume of very finely nucleated water. Thus even if the air supply isturned down or off the water under pressure will not back down the airsupply line feeding the air chamber.

[0014] The metal block which is utilized for the nucleating nozzlehousing is preferably provided with passages through the block in thoseareas where other passages are not required in order to provide maximumcirculation of water through such passages and about the nucleatingnozzle housing and the interior of the snow gun housing to preventfreeze-up by continually permitting the warm water to thoroughlycirculate.

[0015] The snow gun housing may take on different applications or forms,such as a ground level gun or it may comprise the upper end of a snowmaking tower. In the configuration of a tower, the access plug ispositioned in the top end of the tower for access to the filter.

[0016] The apparatus of the present invention thus provides a filterwhich is automatically cleaned upon shutdown of the snow gun by shuttingdown the water supply first. In this event, the remaining air underpressure in the mixing chamber is blown back through the water apertureand purges debris off of the exterior of the filter.

[0017] When the water to the snow gun tower is initially turned on, airis trapped at the top of the snow tower and must be evacuated, otherwisefreeze-up will occur at the top of the snow gun and the snow makingapparatus will become ineffective. With the design of the presentinvention, including the filter at the top of the snow tower, when thehigh pressure water is turned on it is at a much higher pressure thanthe air trapped within the top of the tower, and due to this the trappedair will become purged from the top of the tower and exit through thefilter along with the water under pressure entering the filter.

[0018] With the design of the present invention, as the water jet exitsthrough the exterior nozzle, it is surrounded by air under pressurewhich causes extremely fine and uniform nucleation of the water as itexits to ambient. This water jet also gives mass to the nucleated plumeand projects the plume further from the snow gun than is possible withprior art exterior mixing nozzles and thus causes better intermixingwith other added external water sprays and also the plume is lessaffected on windy days by being misdirected with high winds.

[0019] The exterior nozzle aperture is preferably a round hole. As theair expands when it exits the exterior nozzle aperture, it expandsimmediately and intimately shreds the water jet causing ultra fine andhomogeneous nucleation. This immediate expansion of the air as it exitsalso provides maximum cooling of the nucleated plume.

[0020] The nucleating nozzle combination of the present inventionpermits the use of less air and water to manufacture more quality snowat higher ambient temperatures. For example, prior art snow towersdesigned by the present inventor utilize 50 gallons of water per minutewith the consumption of 50 cfm of air at an ambient temperature of 26degrees F. maximum. The apparatus of the present invention provides anextra fine air-water nucleation stream for external interaction withprimary water sprays wherein the water spray apertures for the extraprimary water sprays may be reduced from ⅛ inch water nozzle aperturesto {fraction (1/16)} inch apertures. Accordingly, the apparatus of thepresent invention can produce more good quality snow using only 15 cfmof air while using only 30 gallons of water per minute at a higherexternal ambient temperature of 28 degrees F.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other objects and advantages appear hereinafter in the followingdescription and claims. The accompanying drawings show, for the purposeof exemplification, without limiting the scope of the invention orappended claims, certain practical embodiments of the present inventionwherein:

[0022]FIG. 1 is a view in partial mid vertical cross section of the snowmaking apparatus of the present invention as seen along section linesI-I of FIG. 2; and

[0023]FIG. 2 is a plan view in horizontal cross section of the apparatusshown in FIG. 1 as seen along section line II-II.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0024] The snow making apparatus 10 of the present invention utilizesair and water under pressure to artificially produce snow and it iscomprised of a metal snow gun housing 11 having independent air andwater chambers 12 and 13 supplying air and water under pressurerespectively to external nozzles 14 in housing 11 for spraying anair-water mixture externally of housing 11 to produce snow insub-freezing ambient atmosphere.

[0025] Three nucleating nozzles 15 are provided and include a blocknozzle housing 16 in which the nucleating nozzles are formed. Nozzlehousing 16 is disposed in snow gun housing 11 and is provided with threepassages 17 through sidewalls of each air chamber 18 which register theair chambers 18 with air supply passages 12 for access of air underpressure through passages 17 from pipe 19 into air chambers 18. Airchambers 18 have an external end 20 and an internal end 21. Water jetapertures 22 are provided on the internal ends 21 with forward endsthereof axially exposed to the interior of respective air chambers 18.The rearward ends of water apertures 22 are exposed to snow gun housingwater chamber 13 via cavity 23 and filter 24 for projecting water jetstreams under pressure through apertures 22 into the respective airchambers 18.

[0026] Exterior nozzles 14 are threadably received into housing 16 atthe external ends 20 of air chambers 18 and each has a nozzle aperture25 therethrough which is axially aligned with water jet stream apertures22 so that the water jet stream exiting into air chambers 18 from waterapertures 22 will be directed on through exterior nozzle apertures 25without engaging the sides thereof and will not be directed or deflecteddownwardly through passages 17 into the air supply.

[0027] Filter 24 is a removable filter closing off the rearward endcavity 23 of water apertures 22 for filtering water supplied from thewater chamber 13. Access plug 26 in snow gun housing 11 is positioned atthe top of the gun 11 for access to and removal of filter 24 which isthreadably received into nucleating nozzle housing 16.

[0028] The filter 24 is a conventional filter which may be found on themarket and which is normally used for air compressors and it iscomprised of a metallic or bronze compressed mesh having filterapertures of no more than 0.010 inches which will prevent any pluggingof water jet stream apertures 22. The outside filter surface of filter24 will self-clean when the snow gun 11 is shut down by closing off thewater supply first. In this event it can be seen that air under pressurewithin passage 17 will exit through water nozzle apertures 22 in reverseand blow debris off the outer surface of filter 24.

[0029] In this representation, the snow gun 11 is shown in the form ofthe upper end of a snow making tower and the water jet stream apertures22 are approximately 0.010 inches in diameter and the exterior nozzlespray apertures 25 are approximately 0.060 inches in diameter. Passages27 are provided through block 16 for circulating water from waterchamber 13 therethrough to keep the warm water moving and to preventfreeze-up at the top of the snow gun housing 11.

I claim:
 1. A snow making apparatus utilizing water and air toartificially produce snow, said apparatus comprising: a metal snow gunhousing having independent air and water chambers therein for supplyingair and water under pressure to at least one nozzle in said housing forspraying air and water externally of said housing to produce snow insub-freezing ambient atmosphere; at least one nucleating nozzleincluding a nozzle housing having an air chamber therein, said nozzlehousing disposed in said snow gun housing and having at least one airaperture through side walls thereof whereby said at least one airaperture registers with said air chamber for access of air underpressure, said air chamber having an external end and an internal end, awater aperture on said internal end with a forward end thereof axiallyexposed to the interior of said air chamber and having a rearward endthereof exposed to said snow gun housing water chamber for projecting ajet stream of water under pressure from said water aperture through saidair chamber, and on through an exterior nozzle aperture on said nozzlehousing at the external end of said air chamber, said exterior nozzleaperture being axially aligned with and larger in diameter than saidwater aperture whereby said water jet stream passes therethrough withoutengaging sides of said exterior aperture; a removable filter closing offthe rearward end of said water nozzle for filtering water supplied fromsaid water chamber; and an access plug in said snow gun housing andpositioned for access to and removal of said filter.
 2. The snow makingapparatus of claim 1 including at least one primary water nozzle in saidsnow gun housing and positioned for spraying water from said waterchamber to ambient atmosphere for interaction with spray from saidexterior nozzle.
 3. The snow making apparatus of claim 2 wherein saidnozzle housing is a metal block including a plurality of said nucleatingnozzles therein with the rearward ends of said water nozzles exiting toa common single rearward end cavity closed off by said filter.
 4. Thesnow making apparatus of claim 3 wherein said exterior nozzles areremovable.
 5. The snow making apparatus of claim 3 wherein said filteris comprised of a metallic mesh having filter apertures of no more than0.010 inches.
 6. The snow making apparatus of claim 5 wherein saidfilter is threadably secured to said nozzle housing.
 7. The snow makingapparatus of claim 6 wherein said water aperture is approximately 0.010inches in diameter and said exterior nozzle spray aperture isapproximately 0.060 inches in diameter.
 8. The snow making apparatus ofclaim 3 including passages through said block and engaged with saidwater chamber for circulating water therethrough.
 9. The snow makingapparatus of claim 3 wherein said snow gun housing comprises the upperend of a snow making tower.
 10. The snow making apparatus of claim 8wherein said plug is positioned in a top end of said tower.